Field of the Invention
The present invention relates to a liquid ejection head used in a liquid ejection apparatus, and to a liquid ejection apparatus.
Description of the Related Art
The liquid supply system typically used in a liquid ejection apparatus is equipped with a main tank that stores liquid internally, a supply unit to which the main tank is removably attached, and a liquid ejection head connected to the supply unit through a supply tube. The liquid ejection head is equipped with a sub-tank section connected to the supply tube, a filter, a liquid chamber connected to the sub-tank section through the filter, an ejection element board that ejects liquid, and a flow channel that connects the liquid chamber and the ejection element board.
Liquid supplied from the supply tube first enters the sub-tank section, passes through the filter to reach the liquid chamber, and after that, passes through the flow channel to be ejected from the ejection element board. In such a liquid ejection head, bubbles containing gas dissolved in the liquid readily accumulate on the downstream side of the filter. If the bubbles adhere to the filter on the downstream side of the filter, the supply of liquid may be blocked in that portion.
Accordingly, Japanese Patent Laid-Open No. 2002-307709 discloses technology in which a partition section provided with ribs is provided inside the liquid ejection head. By supporting the filter with the partition section, and causing the filter and the ribs to abut, the supply of liquid is ensured.
In the configuration of Japanese Patent Laid-Open No. 2002-307709, depending on the temperature and the pressure of the liquid inside the liquid chamber, bubbles are produced, such as dissolved gas bubbles precipitated from the liquid inside the liquid chamber, and bubbles sucked inside from the ejection ports during the ejection of liquid droplets (ejection bubbles). Bubbles accumulate at the top inside the liquid chamber due to buoyancy of the bubbles themselves, but as the flow rate of liquid increases, such as during high-speed printing, the bubbles overcome buoyancy to move into the flow channel on the downstream side together with the liquid and reach the ejection element board, thereby creating a risk of ejection malfunction.